The invention relates to devices and methods for administering, delivering, dispensing or injecting substances. More particularly, it relates to a device and method for blending and administering substances or medicines which are not blended until immediately or very shortly prior to being administered. In one embodiment, the invention relates to a blending and administering device which is suitable for administering an injectable product from a two-chamber ampoule.
In various medical or therapeutic procedures, fluid products consisting of multiple components not blended until shortly prior to being administered, for example, growth hormones, need to be administered to a patient. One way of blending and administering such substances is to use a multi-chamber ampoule. In particular, two-chamber ampoules in which, for example, a fluid is provided as a solvent in a first chamber and a product component is provided in solid and/or fluid form in a second chamber, may be used. The solvent and the product component are blended in the ampoule by means of a blending device. With the aid of the blending device, the fluid product to be injected can be blended, shortly prior to being administered by an administering device, by shifting a plug within the multi-chamber ampoule in such a way that the solvent comes into contact with the product component via a supply channel and mixes with it.
When blending the fluid product, care should be taken that the mixing process is not carried out too quickly. Blending too quickly can lead to foam being undesirably formed in the fluid product. Furthermore, when blended quickly, it is possible for a solid product to not yet be completely dissolved in a solution by the time it is administered, or for a solution of the fluid product to not yet be homogenous.
In a conventional administering device, the multi-chamber ampoule is inserted into a casing of the device. The administering device comprises a blending device in which a drive means can be screwed into the casing with the aid of a thread. The drive means is manually screwed into the casing by a rotating movement in which it moves relative to and into the casing. By rotating the drive means of the blending device in, the plug is slowly moved axially along the ampoule within the multi-chamber ampoule. The rotating movement of the drive means is thus converted into a slow translational movement of the plug within the ampoule, such that a smooth blending is possible within the ampoule.
EP 0 328 699 B1 shows a syringe comprising a blending device, wherein the mixed product is injected into the patient after blending by the administering person pressing a piston rod.
EP 0 298 067 B1 discloses a device for producing an injection solution and for subsequently injecting this solution. Once the mixed product has been blended by the blending device, a product dose to be administered is administered in a controlled way by administering certain doses of the injection solution via a dosing means connected to the holding means of the container.